Taiju is about to confess to the girl he loves when a mysterious force hits the Earth and turns every human into stone. Taiju and his friend Senku wake up thousands of years later and begin to rebuild society. (from manga)

Mizuki Hijiri is a high school girl who just transferred schools. At her new school, she has a fateful encounter with boys suffering from chūnibyō (adolescent delusions of grandeur). There is Noda who dreams of becoming a hero, the tragically handsome otaku Takashima who only likes 2D girls, Nakamura the supposedly "reincarnated" angel or devil, and the self-professed string-puller Tsukumo.